scholarly journals Physical Habitat Simulation with ANFIS Method

10.29007/888p ◽  
2018 ◽  
Author(s):  
Sung-Uk Choi ◽  
Dongkyun Im ◽  
Seung Ki Kim

This study presents physical habitat simulations to investigate the impact of weir removal on the composition of fish community in a river. The study site is a 900 m long reach in the Gongneung-cheon Stream in Korea, at the middle of which the weir was located. Fish monitoring revealed that lentic fishes were dominant before the weir removal, however lotic fishes became dominant after the weir removal. The ANFIS method, a data-driven method, was used for the habitat simulation with River2D for hydraulic simulation. The distribution of highly suitable portion for each fish species were given before and after weir removal. It was shown that the physical habitat simulation successfully predicts the change in the composition of fish community after the weir removal. The simulated results were compared with those from the knowledge- based model.

2018 ◽  
Vol 43 ◽  
pp. 73-83 ◽  
Author(s):  
Dongkyun Im ◽  
Sung-Uk Choi ◽  
Byungwoong Choi

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 942 ◽  
Author(s):  
Hyeongsik Kang ◽  
Byungwoong Choi

This study presents the impact of natural flow patterns on downstream aquatic species habitats in a reach of the Geum River, Korea. The study reach is a 13.4 km long, located downstream of the Yongdam Dam. To assess such an impact, this study performed physical habitat simulations. The River2D model was used for the computation of the flow field and morphology, and the Habitat Suitability Index (HSI) model for the habitat simulation. Three habitat variables—flow depth, velocity, and substrate were used. The Zacco platypus and Baetis fuscatus were selected as the target fish and benthic macro-invertebrate, respectively. Using the building block approach (BBA), the scenarios for modifying dam operations were constructed in the study reach. Scenario 1, scenario 2, and scenario 3 were proposed by using the magnitude–duration concept, base flow allocation concept, and seasonally adjusted minimum flow allocation concept, respectively. Simulation results indicated that the scenarios’ effects significantly increased by about 14.3% for the weighted usable area (WUA). In addition, the morphology change with the restoration of flood events was investigated. It was revealed that the morphology change in the physical habitat simulations further increased by about 13% for the WUA. The change of dam operations through natural flow patterns is more advantageous to aquatic species.


2021 ◽  
Author(s):  
Thibaut Pressat-Laffouilhère ◽  
Clément Massonnaud ◽  
Hélène Bréard ◽  
Margaux Lefebvre ◽  
Bruno Falissard ◽  
...  

Abstract Background: Although data-driven methods for selecting covariates in multivariable models ignore confusion, mediation and collision, they are still used in causal inference. This study, through three real-world datasets, shows the impact of data-driven methods on causal inference. Methods: A research question leading to multivariate model was raised for each of three real-world datasets. Three covariate selection methods were compared on their performances to correctly answer the question: Augmented Backward Elimination with BIC criterion and “change-in-estimate” threshold set at 0.05, Backward Elimination with BIC criterion and a knowledge-based method relying on causal diagrams. The covariates were classified as indispensable, prohibited and optional, considering the potential bias they could cause on the estimate. For each dataset and sample size (N=75, 300 and 3,000), 10,000 Monte Carlo samples were drawn. Percentages of inclusion of each covariate in models were computed. Coverages of Wald’s 95% confidence interval of exposure effects were computed with two different theoretical values (the analysed method, the knowledge-based method).Results: Even with the largest sample size (n=3,000), data-driven methods were not reproducible, with 8.6% to 53% of covariates included in 20% to 80% of experiences. Prohibited covariates could be included in more than 80% of experiences and indispensable covariates missed in more than 80% of experiences even with n=3,000. With the largest sample sizes, coverages of the theoretical knowledge-based value by data-driven methods ranged from 0% to 83.7%; coverages of the theoretical value of the same data-driven method ranged from 73.2% to 91.1% and were asymmetrical. Conclusion: In conclusion, data-driven methods should not be used in causal inference.


2017 ◽  
Vol 7 (6) ◽  
pp. 109 ◽  
Author(s):  
Ebtisam Saleh Aluthman

This study reports the impact of the data-driven learning (DDL) approach on ESL Saudi writers’ general citation patterns that contribute to their general authorial voice. Specifically, the study examines the effects of the DDL activities on ESL writers’ use of integral and non-integral citation patterns based on Swales’ (1981, 1986, and 1990) modal of citation analysis and the extended scheme of classification set by Thompson & Tribble (2001). Guided use of both the Michigan Corpus of Upper-Level Student Papers (MICUSP) and WordandPhrase.info has been designed, implemented, and assessed with a representative sample of 32 ESL upper-intermediate and advanced writers in the Department of Translation in College of Languages at Princess Nourah bint Abul Rahman University (PNU). The effectiveness of the DDL activities in improving the writers’ use of the citation patterns in composition of assignments is measured via a repeated measure paired t test. The study evaluates writers' authorial voice in terms of their use of integral and non-integral citation patterns. The quantitative analysis reveals that participants’ integral patterns (n = 398) of citation significantly outnumbered non-integral patterns (n = 126). The verb-controlling pattern occurred the most (n = 320), constituting 61% of total citation patterns. Results of the paired sample t test reveals a significant statistical difference between participants’ performances before and after the integration of the DDL activities, with the mean value being increased from 2.285 to 3.778. These results inform pedagogical implications of the DDL approach in ESL writing. The conceptual framework implementing the DDL approach in the present study provides guidance for applying corpus-informed tools when designing writing activities for upper-intermediate to advanced ESL learners.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1304 ◽  
Author(s):  
Byungwoong Choi ◽  
Hyeongsik Kang ◽  
Woong Lee

A scientific understanding of the baseflow contribution to streams and watershed processes is critical when dealing with water policy and management issues. However, most previous studies involving physical habitat simulation have been performed without considering the seepage of water from the underground into streams. Motivated by this, herein, we report an investigation of the impact of baseflow using physical habitat simulations for both dominant fish and benthic macroinvertebrate. The study area was located along the reach of the Ungcheon Stream, located 16.50 km downstream and 11.75 km upstream from the Boryeong Dam in the Republic of Korea. For the physical habitat simulation, Zacco platypus and Baetis fuscatus were selected as the target fish and benthic macroinvertebrate, respectively. The HydroGeoSphere (HGS) model (Aquanty Inc., Waterloo, ON, Canada) and the River2D model (Version 0.95a, University of Alberta, Edmonton, AB, Canada) were used for hydrologic and hydraulic simulations, respectively. The Habitat Suitability Index (HSI) model was used for the habitat simulations. Three habitat variables, flow depth, velocity, and substrate, were used. To assess the impact of baseflow, this study performed a physical habitat simulation using each representative discharge, with and without considering baseflow. It was found that the baseflow effects significantly increase the habitat suitability in the study reach. To restore the aquatic habitat, a scenario for modifying dam operations through natural flow patterns is presented using the Building Block Approach (BBA). In the study, the adjusted minimum flow allocation concept was used. It was revealed that the modified dam operations significantly increased the Weighted Usable Area (WUA) by about 48% for both target species. The results indicate that modifying the dam operations through restoration to natural flow regimes but also through inclusion of the baseflow are advantageous to aquatic fish habitats.


2004 ◽  
Vol 55 (2) ◽  
pp. 173 ◽  
Author(s):  
Ian Maddock ◽  
Martin Thoms ◽  
Katarina Jonson ◽  
Fiona Dyer ◽  
Mark Lintermans

The impact of channel morphology and flow on physical habitat availability for the two-spined blackfish (Gadopsis bispinosus) was assessed in the Cotter River, ACT, Australia. Physical habitat requirements for three life stages were identified based on previous field sampling in the Cotter River. Two sites were selected with contrasting channel morphology: Spur Hole, with a moderate gradient and runs and glides, and Vanity’s Crossing, with a steeper gradient, rapids, and fast-flowing pools. Physical Habitat Simulation System (PHABSIM) was used to simulate the flow v. physical habitat availability relationship for each life stage at both sites. Clear differences were apparent between sites, with Spur Hole characterised by increasing habitat with increasing flow and Vanity’s Crossing showing the opposite relationship. The nature of the channel morphology determined this difference, with Spur Hole characterised by marginal zones becoming inundated at higher flows and providing additional suitable physical habitat as discharge increases. Vanity’s Crossing does not contain similar marginal zones. Further analysis demonstrated that high water velocity was the most important factor limiting physical habitat availability at both sites. This approach demonstrates the importance of channel morphology in determining physical habitat availability and an alternative use of PHABSIM to highlight limiting factors for target species.


2001 ◽  
Vol 40 (05) ◽  
pp. 397-402 ◽  
Author(s):  
R. Vergassola ◽  
W. Zong ◽  
M. R. Berthold ◽  
R. Silipo

Summary Objectives: Fuzzy rules automatically derived from a set of training examples quite often produce better classification results than fuzzy rules translated from medical knowledge. This study aims to investigate the difference in domain representation between a knowledge-based and a data-driven fuzzy system applied to an electrocardiography classification problem. Methods: For a three-class electrocardiographic arrhythmia classification task a set of fifteen fuzzy rules is derived from medical expertise on the basis of twelve electrocardiographic measures. A second set of fuzzy rules is automatically constructed on thirty-nine MIT-BIH database’s records. The performances of the two classifiers on thirteen different records are comparable and up to a certain extent complementary. The two fuzzy models are then analyzed, by using the concept of information gain to estimate the impact of each ECG measure on each fuzzy decision process. Results: Both systems rely on the beat prematurity degree and the QRS complex width and neglect the P wave existence and the ST segment features. The PR interval is not well characterized across the fuzzy medical rules while it plays an important role in the data-driven fuzzy system. The T wave area shows a higher information gain in the knowledge based decision process, and is not very much exploited by the data-driven system. Conclusions: The main difference between a human designed and a data driven ECG arrhythmia classifier is found about the PR interval and the T wave.


2005 ◽  
Vol 62 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Nicolas Lamouroux ◽  
Ian G Jowett

Conventional instream habitat models (e.g., the physical habitat simulation system) predict the impact of regulation on the habitats of freshwater taxa. They link a hydraulic model with microhabitat-suitability models for taxa to predict habitat values at various discharge rates. Their use requires considerable field effort and experience. Recent analyses performed in France suggested that comparable results could be achieved using simplified hydraulic data. We tested this approach for 99 stream reaches and nine aquatic taxa in New Zealand. The resulting generalized habitat models predict habitat values similar to those predicted by conventional models from simplified hydraulic data (depth–discharge and width–discharge relationships, average particle size, and mean annual discharge). As in France, within-reach changes in habitat values were linked to the specific discharge of reaches, while between-reach changes depended mainly on the Froude number at mean annual discharge. The generalized models perform well outside their calibration range. Models previously developed in France perform well in New Zealand. Such generalized models contribute to identifying the key hydraulic variables for freshwater taxa and should facilitate habitat studies worldwide.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Daniel Van Kalsbeek ◽  
Karl Enroth ◽  
Elizabeth Lyden ◽  
Mark E. Rupp ◽  
Christopher J. Smith

Abstract Background Point-of-care ultrasound (POCUS) devices are becoming more widely used in healthcare and have the potential to act as fomites. The objective of this project was to study the thoroughness of cleaning of POCUS machines before and after a quality improvement initiative. We designed a mixed-methods, pre/post study which took place over the course of one year at a university-affiliated health center. Cleaning rates of four ultrasound machines used by hospital medicine and critical care medicine services were evaluated using fluorescent marking. Interventions targeted physicians’ knowledge of best practices and improved access to cleaning supplies. Pre- and post-intervention cleaning rates were compared using a generalized linear model. The impact of the corona virus disease of 2019 (COVID-19) pandemic on baseline cleaning rates was also evaluated. Physicians’ attitudes and knowledge of cleaning practices were evaluated via unpaired pre/post surveys. Results There was significant improvement in thoroughness of cleaning following intervention (pre 0.62, SE 0.05; post 0.89, SE 0.07), p < 0.0001). There was no difference in baseline cleaning rates before (0.63, SE 0.09) and after (0.61, SE 0.1) the onset of the COVID-19 pandemic (p = 0.78). Post-intervention surveying found improved understanding of guideline-based cleaning practice, better performance on knowledge-based questions, and fewer reported barriers to machine cleaning. Conclusion Thoroughness of cleaning of POCUS machines can be improved with practical interventions that target knowledge and access to cleaning supplies.


2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.


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